Why Lakes In Hyderabad Could Not Prevent Flood – Free PDF Download

Background

• The man-made Hussainsagar lake was Hyderabad’s main drinking water source till the early part of the last century.
• But even as the city, established by Muhammed Quli Qutb Shah of the Qutb Shahi dynasty in 1591, expanded beyond the fortified walls of the Golconda,
• The heart-shape lake built across a tributary of the river Musi, was only one of the several hundreds of lakes that dotted the region.

Number of lakes

• In less than a century, the city has expanded from 55 sq.km to 625 sq.km under the Greater Hyderabad Municipal Corporation (GHMC).
• The jurisdiction of the Hyderabad Metropolitan Development Authority (HMDA) spreads over 7,257 sq.km covering parts of a few neighbouring districts as well, and had 2,800 lakes as per as 2017 estimate.

Why they were created?

• The water bodies were created for drinking water and irrigation purposes at a time when water management was considered crucial in this otherwise arid region for centuries.
• This network of man-made water bodies, interconnected by several natural waterways, ultimately led to the River Musi in most cases.
• Along with these small lakes, in the aftermath of the 1908 floods in Hyderabad,
• The Nizam government commissioned two big reservoirs, Osman Sagar and Himayat Sagar,
• On the periphery of the city to regulate the water flow from Musi and its tributary Esa.

Vanishing of rivers

• Discharge of sewage and industrial effluents, encroachments by government and private individuals, and decades of neglect had everyone thinking the river would never flow again.
• Most of the former waterways are open sewers now.
• But, on October 13, the river was in spate once again after a record downpour.
• Low-lying localities and colonies that were built on the lake beds and nullahs were submerged in no time.
• Many days later, hundreds of these colonies were still under water.

Krishna & Godavari

• Based on hydrology, present-day Hyderabad can be divided into Krishna and Godavari basins.
• In both Krishna and Godavari basins, the city has a network of lakes and drains which carry the excess water from one to another and then finally into the Musi and Majeera rivers.

• Senior Hydrogeologist BV Subba Rao says lakes were built in the past based on the natural topography and rainfall trends.
• “These were not created for flood control mitigation but as draught mitigation structures.
• Every 2 sq.km had a lake to ensure water for drinking and irrigation purposes to every habitation.”

The forgotten lakes

• Over the years, owing to the expansion of the city, the lakes were not in demand for their primary purposes of irrigation and drinking water.
• But they continued to be relevant for flood regulation.
• Despite this, in the last few decades, several colonies, as well as large real estate ventures, have come the buffer area — of lakes, large water bodies,
• That existed for centuries have shrunk in size, encroachments have eaten into natural waterways, and stormwater drains get easily clogged.

Loss due to flood

• As many as 33 lives have been lost to heavy rains and floods in the city, with the GHMC estimating that at least 37,409 families have been affected.
• The Municipal Administration minister pegged the city’s losses at Rs 670 crore.

Q) Which of the following best explain why the lower course of a river is sometimes chocked with sediments?

1. Much of the river water is drawn for irrigation in the lower course.
2. The valley of a river is widest in its lower course.
3. The velocity of a river in its lower course is low.
4. The delta sometimes develops in a rivers lower course.

1. 1, 2 & 3 only
2. 2 & 4 only
3. 2, 3 & 4 only
4. All of the above

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